WO2004098264A1

WO2004098264A1 - Mower tractor

Info

Publication number: WO2004098264A1
Application number: PCT/JP2004/006234
Authority: WO
Inventors: Toshitaka Komiya; Toshihiko Ibe; Takatoshi Meno; Hideki Amano; Yasuhiro Ikegami
Original assignee: Yanmar Co. Ltd.
Priority date: 2003-05-08
Filing date: 2004-04-28
Publication date: 2004-11-18
Also published as: US7451587B2; US20060090442A1

Abstract

A mower tractor (1), comprising a mid-mount type mower (5) located at the abdominal region of a body frame between front wheels (2, 2) and rear wheels (3, 3), wherein the input shaft (58) of a transmission case (24) is disposed on the body frame (8) eccentrically to the lateral one side thereof, the input shaft (58) is connected to the output shaft (55) of an engine (23) through a transmission shaft (14) and a universal joint (27), and an elevating/lowering regulating device (60) is disposed between the transmission shaft (14) and the body frame (8).

Description

TECHNICAL FIELD The present invention relates to a mower tractor provided with a mid-mount mower in a lower abdomen between a front wheel and a rear wheel, a lifting link mechanism of a moud mount mower, and a mower height regulating device. is there. 2. Description of the Related Art Conventionally, the technology of a lifting device for a mid-mount mower that has been configured so that it can be lifted by attaching a midmount mower to the lower abdomen of the step between the front and rear wheels of the tractor is disclosed in Japan It is publicly known as described in 5 2 2 4 publication.

Such a power transmission mechanism of the mount mount mower transmits the power from the engine via a belt from the engine pulley or a universal joint, etc. First of all, it was transmitted to the countershaft behind the blade shaft, and it was driving the mittmund mower.

In addition, the front part of the tractor and the front part of the mower are rotatably connected via the front link, and a support member is provided in the middle part of the front and rear of the tractor to connect the front part of the lift link so that it can rotate freely. An elevating cylinder is arranged, the elevating cylinder is extended to the rear of the mower, and the elevating cylinder and the lift link are rotatably connected via an intermediate link to form an elevating link mechanism, and the midmount mower is raised and lowered Adjustable.

However, in a conventional midmount mower elevating device, the engine crankshaft and the HST transmission input shaft are integrally configured in the clutch housing and arranged on the same line. The drive shaft was located at the center position in the left-right direction of the fuselage below the rank shaft and the HST transmission input shaft, so there was no space on the circumference of the drive shaft and there was no design margin.

In addition, the clutch housing is equipped with a bracket for mounting the lift control device for the midmount mower on the fuselage frame, and the bracket is fastened with bolts, etc., so there are many parts. It was a disadvantage in terms of cost.

Furthermore, since the brackets are arranged, it is difficult to occupy space and secure a design margin. DISCLOSURE OF THE INVENTION In view of the above-described problems, in the present invention, a space is provided on the circumferential side of the drive shaft in the clutch housing, thereby providing a design allowance and a mid-mount mower in the secured space. The elevating / lowering link mechanism and the elevating / lowering regulating device can be arranged. The objective is to reduce the number of parts and to reinforce the fuselage frame.

That is, according to the present invention, a mower tractor having a muffler mower on the lower abdomen between the front wheel and the rear wheel, the input shaft of the mission case being arranged so as to be biased to the left and right sides of the machine frame, the input The shaft and the output shaft of the engine were connected via a transmission shaft and a universal joint, and a lifting restriction device was disposed between the transmission shaft and the machine frame.

As a result, a space can be secured on the side opposite to the side where the input shaft is disposed, and an elevating restriction device or the like can be incorporated into the airframe. In addition, it is possible to arrange the lifting control device within the airframe surrounded by the airframe frame with a design margin.

Preferably, a reinforcing bracket is horizontally provided between the left and right body frames at the front lower side of the input shaft of the mission case, and the lifting restriction device is disposed on the reinforcing bracket. As a result, the bracket for arranging the lifting control device and the reinforcing bracket can be shared by a single bracket, and the number of parts can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing the overall configuration of a mower tractor according to the present invention. FIG. 2 is a side view showing the internal structure of the mower tractor. FIG. 3 is also a plan view.

FIG. 4 is an enlarged plan view showing the configuration of the front part of the mission case. FIG. 5 is a side view showing the configuration of the lifting link mechanism of the midmount mower.

FIG. 6 is an enlarged plan view showing a configuration of a space portion sandwiched between the engine and the transmission case.

FIG. 7 is a plan view showing the internal structure of the mower tractor in the second embodiment.

FIG. 8 is an enlarged plan view showing the structure of the front part of the mission case.

FIG. 9 is a side view showing the configuration of the lifting link mechanism of the mower tractor in the second embodiment.

FIG. 10 is a perspective view showing the configuration of the mower height regulating device. FIG. 11 is a schematic view showing another embodiment of the lifting link mechanism. FIG. 12 is a schematic view showing a link mechanism of the brake device.

FIG. 13 is a view showing another embodiment of the regulating member.

FIG. 14 is a plan view showing the relationship between the engine and the frame. Figure 15 is also a side view.

Figure 16 is also a rear view.

FIG. 17 is a plan view showing the arrangement configuration of the operation pedal. FIG. 18 is a plan view showing the structure of the shift pedal.

Figure 19 is also a side view.

FIG. 20 is a schematic diagram showing the operational configuration of the pedal.

FIG. 21 is a diagram showing the configuration of the speed holding mechanism.

FIG. 22 is a side view of the arm of the speed holding mechanism.

FIG. 23 is a plan view showing another embodiment of the shift pedal connecting portion.

FIG. 24 is a side view showing the structure of the brake pedal.

FIG. 25 is also a plan view.

FIG. 26 is a view showing a parking brake mechanism.

BEST MODE FOR CARRYING OUT THE INVENTION First, an overall configuration of a mower tractor equipped with a mower height regulating device according to the present invention will be described.

As shown in Figs. 1 and 2, the mower tractor 1 supports the front wheels 2 and 2 at the front of the fuselage and the rear wheels 3 and 3 at the rear, and the engine 2 in the hood 4 on the front of the fuselage frame 8 3 is stored. At the front and middle of the body frame 8 is equipped with a lifting mechanism 11 that can be moved up and down by attaching a front working machine such as a dozer or bucket fork. It is composed of a “U” shaped boom, a hydraulic cylinder, and so on. A dashboard 9 is connected to the rear of the ponnet 4, a steering handle 6 protrudes from the dashboard 9, a driver's seat 7 is arranged at the rear thereof, and the fuselage between the rear of the bonnet 4 and the driver's seat 7. Step 1 0 is placed on frame 8. A main transmission lever, a position lever, and the like are disposed on the side of the driver's seat 7. A gate-like R 0 P S frame 12 is suspended across the left and right sides of the fuselage frame 8 on the rear side of the driver's seat 7. Further, a midmount mower 5 is attached to the lower abdomen of the step 10 disposed between the front wheels 2 • 2 and the rear wheels 3, 3 via a lifting link mechanism described later.

A mission case 24 is disposed below the driver's seat 7, The cushion case 2 4 is connected to the fuselage frame 8 fixed to the front. The power of the engine 23 is input into the mission case 24 via a damper, a drive shaft, an engine output shaft 55, and a transmission shaft 14 housed in the body frame 8. The engine input shaft 5 8, the front wheel drive shaft 15, and the Mits PTO shaft 16 protrude from the front surface of the transmission case 24. The power output from the front wheel drive shaft 15 is transmitted to the front axle case 28 via the universal join rod 25, and the front wheel 2 attached to the front axle 30 protruding from both sides of the front axle case 28. · Drive 2 The power output from the mid PTO shaft 16 is transmitted to the midmount mower 5 via the universal joint 26.

A rear axle case 29 is attached to both sides of the rear portion of the transmission case 24 to support the rear axle 31, and a rear wheel 3-3 is attached to the rear axle 31. The front side of the transmission case 2 4 is equipped with an HST transmission 4 1, which is a rear wheel by operating the forward travel pedal 6 8 F and reverse travel pedal 6 8 R arranged below the driver's seat 7. 3 · 3 drive direction and drive speed can be set arbitrarily. Place the hydraulic case 1 3 on the upper surface of the mission case 2 4, project the lift arm 4 2 from the hydraulic case 1 3, and lift rod 3 between the lift arm 4 2 and the lower link 4 3. 9 is connected, and a top link 40 protrudes from the rear surface of the hydraulic case 13 to form a three-point link type work machine mounting device 53. A rear PTO shaft (not shown) protrudes from the rear surface of the mission case 24. The work machine mounted on the work machine mounting device 53 is driven by the power output from the rear PTO shaft. I have to.

Also, the midmount mower 5 placed on the lower abdomen of the step 10 between the front wheels 2 and 2 and the rear wheels 3 and 3 is located on both sides of the front and rear of the mower deck 17 (Fig. 3). The grounding wheel 1 8 · 1 8 · · · can be adjusted up and down, the blades are housed in the mode 1 7, and the gear box 2 2 is located at the approximate center of the upper surface of the mower deck 1 7 A universal joint is installed between the input shaft 20 projecting rearward from the gear box 2 2 and the mid-protrusion PTO shaft 16 projecting forward from the lower front part of the transmission case 24. It is connected at position 26 so that power can be transmitted.

Next, the midmount moat lifting link mechanism will be described. As shown in FIGS. 2 to 5, two hooks 3 2 and 3 2 protrude from the front of the mower deck 17 to the front, and the front link 3 5 is provided on the hooks 3 2 and 3 2. The front side of the CFC link 35 is pivotally supported by a support plate 36 fixed to the front of the fuselage frame 8, and the front side of the midmount mower 5 is placed at the upper front of the fuselage. It is suspended. Further, a pair of mower support mechanisms 45 and 45 are provided on the left and right sides of the upper surface of the modec 17.

The mower support mechanism 45 includes a mounting stay 46 fixed to the mower deck 17, a plate-like lift link 47 connected to the mounting stay 46, and a U-shaped bracket for suspending the lift link 47 And an intermediate link 48 composed of a wire and the like, and a shaft link 49 fixed to both ends of a midlock shaft 56 described later.

The shaft link 49 has an arm portion 49a projecting from a pipe-shaped boss portion, and the intermediate link 48 is connected to a hole drilled at the tip of the arm portion 49a via a pin or the like. The other end (lower end) of the intermediate link 48 is pivotally supported by the lift link 47. The lift link 47 has one end fixed to the mounting stay 46 and the other end supported by a support stay 50 fixed to the body frame 8.

With such a configuration, the midmount mower 5 can be moved up and down by rotating the midlock shaft 56.

The intermediate link 48 can also be constituted by a chain. That is, by configuring the intermediate link with a chain, it is possible to pivotally support the connecting portion between the intermediate link and the lift link 47 and the connecting portion between the intermediate link and the arm portion 4 9a of the shaft link 49. Since there is no need to provide a mechanism, the number of parts can be reduced. In addition, when configured with a U-shaped bracket, there is a risk of bending when a load is applied. However, when configured with a chain, it can be bent freely, so that damage can be prevented.

The mid lock shaft 56 is composed of a cylindrical rod body, Projecting from the fuselage frame 8 and is mounted horizontally. A locking plate 59 and a stopper 61 constituting the mower height restricting device 60 are fixed on the circumference of the mit lock shaft 56, and projecting portions project in the same radial direction. Thus, the projecting portion is disposed at a position where it does not contact the transmission case 24 within the rotation range of the midlock shaft 56.

One end of a mower elevating link 37 is pivotally supported on the connecting plate 59, and a lift arm 4 disposed at the rear of the machine body via a swing bracket 38 on the rear end side of the mower elevating link 37. The mower elevating link 37 is moved back and forth as the lift arm 42 rotates.

When the mower elevating link 37 is pulled rearward, the connecting plate 59 fixed to the midlock shaft 56 rotates to the rear side, and the midlock shaft 56 rotates to the midmount mower. 5 rises.

As described above, the lifting mechanism of the midmount mower 5 is configured, and when the rear lift arm 42 is operated by operating the lifting lever provided near the driver's seat 7, the midmount mower is mounted via the mower lifting link 37. The mower 5 can be moved up and down.

Next, the configuration of the front part of the mission case 24 in which the elevation restricting device 60 of the Mitt mount mower 5 is arranged will be described.

As shown in FIGS. 4 and 6, a reinforcing bracket 6 4 is horizontally installed between the left and right aircraft frames 8 and 8, and the reinforcing bracket 6 4 is formed of a plate, The rigidity of the fuselage frame 8 · 8 is strengthened. A case of the mower height regulating device 60 is fixed on the right side of the reinforcing bracket 64. The connecting plate 59 is disposed on the left side in the aircraft traveling direction, and is disposed on the left side of the front part of the HST transmission 41 disposed in the front part of the mission case 24 so as not to contact. . A universal joint 27 is disposed above the midlock shaft 56, and a transmission shaft 14 is disposed between the universal joint 27 and the universal joint 51. The output shaft 5 5 of the engine 2 3 protrudes rearward from the left and right center, and the input shaft 5 8 protrudes from the front of the HST transmission 4 1 from the left and right center. Is also shifted to the left. In other words, the HST transmission 41 is arranged slightly on the left side from the center of the left and right body frames 8 and 8, and the space surrounded by the right body frame 8 and the transmission shaft 14 is widened. ing. In this way, the space is widened and the mower height regulating device 60 is arranged.

Further, the stopper 61 constituting the mower height regulating device 60 is fixed so as to protrude upward on the right side of the mid-port shaft 56 in the aircraft traveling direction. The stopper 61 is formed in a substantially inverted L shape when viewed from the side, and the tip of the stopper 61 is in contact with the outer periphery of the restricting member 44. The regulating member 44 is accommodated in a U-shaped case 4 4 b having a side view, and the lower portion of the case 44 b is fixed on the reinforcing bracket 64. In other words, the reinforcing bracket 6 4 is installed horizontally on the left and right fuselage frames 8 • 8 in front of the midlock shaft 56.

The restricting member 44 is formed in a substantially disk shape, and the upper surface of the restricting member 44 is formed in a step shape so that the height gradually increases, and the upper surface of the stopper 61 is formed on the upper surface. The height of the mid-mount mower can be controlled by contacting the tip. In other words, the upper surface of the restricting member 44 has a substantially fan-shaped contact surface provided at equal angles, and the height of the contact surface is gradually increased or decreased in the circumferential direction. An operating shaft 44a is vertically installed at the center of the regulating member 44, an operating member (not shown) is connected to the upper end of the operating shaft 44a, and the operating member is rotated to move the mower. Can be adjusted. In other words, by rotating the restricting member 44, the position of contact with the upper surfaces of the stopper 61 and the restricting member 44 can be changed. The rotation angle of 6 can be restricted, and the height of the midmount mower, that is, the cutting height can be changed.

Further, a plurality of steps having different distances from the rotation axis may be provided on the outer peripheral surface of the restricting member, and a stopper may be supported by the steps to restrict the rotation angle of the midlock shaft 5 6.

Next, the configuration of the mower height regulating device 160 according to another embodiment will be described with reference to FIG. This will be explained with reference to FIG.

As shown in FIG. 8, a reinforcing bracket 6 4 is horizontally installed between the left and right body frames 8 and 8, and the reinforcing bracket 6 4 is constituted by a plate body. · The rigidity of 8 is strengthened. A case of a mower height regulating device 1 60 is fixed on the left side of the reinforcing bracket 6 4, and the mower height regulating device 1 6 0 is arranged on the longitudinal axis of the mower elevating link 3 7. . A cylindrical midlock shaft 5 6 is horizontally mounted between the left and right body frames 8, 8, and a connecting plate 5 9 is fixed on the circumference of the midlock shaft 5 6.

The connecting plate 59 is formed in a substantially L shape in a side view, and also serves as a part of the mower height regulating device 60. The connecting plate 59 is arranged on the left side of the clutch housing 33 on the left side in the aircraft traveling direction, and is located on the left side of the front part of the HST transmission 41 located on the front part of the transmission case 24. Is arranged. A universal joint 27 is disposed above the midlock shaft 56, and a transmission shaft 14 is disposed between the universal joint 27 and the universal joint 51. The output shaft 5 5 of the engine 2 3 protrudes rearward from the left and right center, and the input shaft 5 8 that protrudes from the front of the HST transmission 41 is shifted to the left of the left and right center of the output shaft 5 2. Yes. In other words, the HST-type speed change device 41 is arranged slightly on the left side from the center of the left and right airframe frames 8 and 8, and the space surrounded by the right airframe frame 8 and the transmission shaft 14 is widened. It is said.

Further, the connecting plate 59 is bent forward to form a claw portion. The claw portion is used as a contact portion 59 b of the regulating member 104 and the mower height regulating device 160 It can function as a stagger. A pin hole 59a is drilled in the vicinity of the bent portion of the connecting plate 59, and a pin is fitted into the pin hole 59a and the pin hole 37a drilled at the tip of the motor lifting link 37. The connecting plate 59 and the mower elevating link 37 are connected to each other.

The mower height regulating device 160 has a substantially disc shape, and is configured to be rotatable about the adjusting shaft 75, and its upper surface is spiral. It is shaped like a staircase that is gradually lowered or raised in the direction of rotation by a certain height. The adjusting shaft 75 and the restricting member 10 4 are configured to be able to rotate integrally, and by rotating the adjusting shaft 75, the restricting member 10 4 is rotated, and the contact portion of the tip of the connecting plate 5 9 5 9 b is allowed to contact the upper surface of the regulating member 10 4. The height position of the upper surface of the restricting member 104 restricts the rotational angle of the midlock shaft 56 on the mower lowering side. As another form of the restricting member 104, it is also possible to use a restricting member 114 having a plurality of steps with different distances from the rotation axis on the outer peripheral surface.

As shown in FIG. 13, the restricting member 1 1 4 of the present embodiment is housed in a case 1 1 4 b formed in a U-shape when viewed from the side, and the case 1 1 4 b is a reinforcing bracket. 6 is supported by a support 69 fixed to 4. Further, a plurality of steps having different distances from the adjustment shaft 75 serving as the rotation axis are provided on the outer peripheral portion 1 14 a of the restriction member 1 14. That is, a contact portion is formed in which the diameter of the restricting member 1 1 4 becomes longer in the rotation direction by a predetermined length. Then, by rotating and adjusting the adjustment shaft 75, the regulating member 1 1 4 is rotated, and the position of contact with the contact portion 5 9 b at the end of the connection plate 5 9 can be changed, and the connection plate By changing the rotation position of 5 9, the rotation angle of the midlock shaft 5 6 can be restricted, and the mower height can be restricted.

As described above, the contact portion 59b provided on the connecting plate 59 that constitutes the lifting link mechanism of the mid-mount mower constitutes a part of the mower height regulating device 160, so that each is provided separately. Compared to the case, the number of parts can be reduced and the space can be saved. In addition, the welded part can be reduced.

Further, in the above description, the connecting plate 59 is fixed on the middle lock shaft 56 from the left side of the body frame 8 · 8, and the mower is moved up and down through the connecting plate 59. Although power is transmitted, power transmission for raising and lowering the mower can also be performed via a connecting arm 71 disposed at a substantially central portion in the longitudinal direction of the midlock shaft 56. In other words, as shown in Fig. 11 The intermediate shaft 80 is arranged in parallel, and both end portions of the intermediate shaft 80 are protruded from the left and right body frames 8 and 8, and the boss portion of the sub link 81 is fixed to the left and right end portions. The tip of the sub-link 81 protrudes rearward and downward, and is connected to a mower elevating link 37. A hydraulic lift (not shown) is connected to the mower elevating link 37 so that the intermediate shaft 80 can rotate. It is configured.

On the connecting arm 71 projecting rearward and downward from the middle part of the left and right of the midlock shaft 56, the intermediate arm 82 projecting forward from the middle part of the left and right of the intermediate shaft 80 is rotatable to the tip. The provided bearing 8 2 a is in contact. When the intermediate shaft 80 is rotated, the midlock shaft 56 is rotated via the connecting arm 71 so that the midmount mower can be moved up and down.

In such a configuration, the mower elevating link 37 is pulled rearward when the lift arm 42 is turned upward, and the intermediate arm 82 is rotated downward by pulling the mower elevating link 37. By moving, the connecting arm 7 1 can be turned downward to raise the midmount mower. Thus, since all the loads applied to the mower elevating link 37 are tensile loads, buckling of the mower elevating link 37 can be prevented. Further, since the connecting arm 71 and the intermediate arm 82 are connected by the contact of the bearing 82a, the frictional resistance generated between the arms 71 and 82 can be reduced. It becomes possible to rotate 5 6 · 80 smoothly. In addition, the linkage. It is possible to prevent damage to the rate 5 9 and the intermediate arm 8 2, and it is not necessary to process each arm 5 9 · 8 2 with a long hole to prevent damage.

Furthermore, since the power transmission for raising and lowering the mower is performed at a substantially central portion in the longitudinal direction of the midlock shaft 56, the twist of the midlock shaft 56 can be prevented. It is possible to move up and down in parallel. Further, by providing the sub link 8 1 at one end of the intermediate shaft 80 outside the fuselage frames 8, 8, there is no interference between the mower elevating link 37 and the mission case, and the inside of the fuselage frame 8 Special Source.

Next, a brake interlocking mechanism that interlocks the brake pedal 61 and the brake device will be described.

As shown in FIG. 8, a brake pedal 1 6 1 is provided at the lower left of the driver's seat 7, and the brake pedal 1 6 1 is connected to a long rod 1 6 5 via a brake arm 1 6 2. It is linked to a brake device (not shown) located at the rear of the aircraft.

The brake pedal 16 1 is configured to be rotatable about a fulcrum shaft 10 5 pivoted on the body frame 8, and a brake arm 1 6 2 is provided at the left end of the fulcrum shaft 1 0 5. A long rod 1 6 5 is connected to the brake arm 1 6 2. The long rod 1 65 extends to the rear of the aircraft along the left aircraft frame 8 and is connected to the brake actuator overnight via a cam lever shaft.

When the brake pedal 1 6 1 is depressed, the brake actuator overnight is rotated to operate the brake device, and the rear wheels 3 and 3 are braked.

In such a brake device link mechanism, when the mid-mount mower 5 is configured to be movable up and down by the mid-lock shaft 5 6 as described above, the intermediate mount 4 that is a hanging bracket of the mid-mount mower 5 is used. 8 was an obstacle to the brake interlock mechanism of the brake device. In addition, when the brake interlocking mechanism is arranged at a high position, the fulcrum shaft 1 0 5 of the brake pedal 1 61 is in the high position, and the space between the fulcrum shaft 1 0 5 and the main body frame is narrowed. The brake arm 6 2 provided at the left end of the fulcrum shaft 105 may interfere with the main body frame.

For this reason, as shown in Fig. 12, the second fulcrum shaft 1 6 7 is provided separately from the fulcrum shaft 1 0 5 of the brake pedal 1 6 1 so that the brake link mechanism and the main frame do not interfere with each other. It can also be configured.

In other words, the second fulcrum shaft 1 6 7 is separately provided on the airframe frame on the front side of the fulcrum shaft 1 0 5 of the brake pedal 1 6 1 and protrudes below the fulcrum shaft 1 0 5. Fixed to the end of the brake arm 1 6 2 and the second fulcrum shaft 1 6 7 The bracket 1 5 8 is connected with the wire 1 6 3 etc., and the end of the second fulcrum shaft 1 6 7 is connected to the second bracket 1 5 7 at a position facing the bracket 1 5 8. The rods 1 6 5 are connected to form an interlocking mechanism for the brake device.

Thus, the second fulcrum shaft 1 6 7 is provided separately from the fulcrum shaft 1 0 5 of the brake pedal 1 6 1, the brake arm 1 6 2 is provided on the second fulcrum shaft 1 6 7, and the long rod 1 6 5 As a result, the interlocking mechanism of the brake device can be placed at a high position, and the space can be used effectively. In addition, since the brake arm 1 6 2 and the main body frame do not interfere with each other, the length of the brake arm can be increased and the reliability of the link structure can be improved.

Next, the engine mounting structure will be described.

Fig. 14 is a plan view showing the relationship between the engine and the frame, Fig. 15 is a side view, and Fig. 16 is a rear view.

The fuselage frame 8 has a ladder frame structure in which two plate-like members extending in the front-rear direction are connected by connecting members arranged in the left-right direction. The engine 23 is fixed to the fuselage frame 8 at a substantially central portion in the front and rear of the fuselage frame 8. At the top of the fuselage frame 8, stays 1 2 1 · 1 2 1 and stays 1 2 2-1 2 2 are provided. The stage 1 2 1 · 1 2 1 supports the front of the engine 2 3 via anti-vibration rubber. The stay 1 2 2-1 2 2 has the engine 2 3 fixed to the fuselage frame 8. It is to be established. The engine 2 3 is connected to the stage 2 2 · 2 2 via a connecting member 1 1 8. The connecting member 1 1 8 is made of aluminum or the like, and is made of a highly rigid member. The rear part of the engine 2 3 is fixed to the body frame 8 via the connection member 1 1 8.

The engine 23 is supported at the front by anti-vibration, and is rigidly mounted on the fuselage frame 8 at the rear. In an engine that is supported at four points with respect to the fuselage frame 8, two points on the output shaft side or the flywheel side are fixed to the fuselage frame 8. This prevents misalignment between the engine 23 and the transmission shaft, and reduces noise and noise. Vibration is reduced. In addition, the amplitude of engine 23 during sudden acceleration and deceleration can be reduced, increasing the degree of design freedom for electrical components and piping installed in engine 23, making it possible to compact the engine.

In addition, since the engine run-out is restricted near the flywheel with a large rotational moment, the burden on the bearing portion of the output shaft near the flywheel can be reduced. Furthermore, since the flywheel with a large gyro effect is not moved greatly, the responsiveness of the engine can be improved.

Next, the arrangement configuration of the operation pedal will be described.

FIG. 17 is a plan view showing the arrangement of the operating pedal.

Brake pedals 6 1 L · 6 1 R and shift pedals 6 8 F · 68 R are arranged on the left and right sides of the body frame 8, respectively. Pre-bleed pedals 6 1 L · 6 1 R are arranged side by side and connected to the brake mechanism of the rear wheel via a link mechanism. By depressing the brake pedal 6 1 L, the rod 1 40 connected to the brake mechanism of the left rear wheel drive device slides and brakes the left rear wheel. Similarly, in the brake pedal 6 1 R, the rod 1 3 9 is rocked and the right rear wheel is braked.

The shift pedal 6 8 F · 6 8 R is attached to the outer surface of the fuselage frame 8 via the shift pedal connection 1 3 3. The shift pedal connecting part 1 3 3 is connected to the operation part 1 3 8 of the HST 4 1 via a link mechanism, and performs the shifting operation of the HST 4 1 according to the operation of the shift pedal 6 8 F · 6 8 R. Is. Arm 1 3 6 is connected to variable speed pedal connection 1 3 3, and arm 1 3 6 is connected to H S T operation section 1 3 8 by rod 1 3 7. The operation of the shift pedal 6 8 F · 6 8 R is transmitted to the arm 1 3 6 through the shift pedal connection 1 3 3 and the H ST 4 1 is operated.

The arms 1 3 6 are disposed inside the body frame 8. As a result, the mouth 1 3 7 that connects the arm 1 3 6 and the HST operation unit 1 3 8 can be arranged along the inside of the fuselage frame 8, and the HST operation unit 1 3 8 can be configured compactly. it can. The link mechanism from the arm 1 3 6 to the HST operation unit 1 3 8 can be easily protected by the body frame 8. further, Since the link mechanism from the arm 1 3 6 to the HST operation section 1 3 8 is installed inside the fuselage frame 8, the link mechanism of the work implement and the link for the speed change operation Interference can be easily avoided.

Arm 1 3 6 is used to fix shift pedal 6 8 F · 6 8 R at a fixed angle, and to keep the traveling speed of the work vehicle constant, and is composed of a ratchet body. The arm 1 3 6 serves as a member for operating the HS T4 1 and a member for maintaining the variable speed pedal 6 8 F · 68 R at a constant angle. As a result, the functions for HST operation are unified in the arms 1 3 6 and the number of parts can be reduced, and the HST operation mechanism including the holding mechanism at a fixed angle can be configured in a compact manner, and the space for the fuselage frame 8 can be reduced. It can be used effectively.

Next, the configuration of the shift pedal 6 8 F · 68 8 R and the arm 1 3 6 will be described in detail.

FIG. 18 is a plan view showing the structure of the shift pedal, and FIG. 19 is a side view of the same.

The shift pedal 6 8 F is a forward pedal and is fixed to the spindle 14 1. An L-shaped arm 143 and an arm 1 3 6 are fixed to the support shaft 1 4 1, and the variable speed pedal 6 8 F, the L-shaped arm 1 4 3 and the arm 1 3 6 rotate integrally.

The shift pedal 6 8 R is a reverse pedal and is fixed to the support shaft 142. A contact arm 145 is fixed to the support shaft 142, and the speed change pedal 6 8 R and the contact arm 145 rotate integrally.

The L-shaped arm 144 is fixed to the support shaft 144 at the corner, a damper 144 is connected to the front end, and a roller 148 is rotatably arranged at the rear end. Since the damper is connected to the front end, it is possible to easily avoid the interference between the link mechanism of the work implement and the link for shifting operation when a Mitsmund mower or the like is provided.

The roller 148 is in contact with an abutment lever 1 45 disposed behind the L-shaped arm 14 3. L-shaped arm 143, contact arm 1 45 is disposed in the shift pedal connecting portion 1 3 3.

By connecting the damper 144 to the L-shaped arm 143, the shifting pedal is prevented from suddenly returning to the neutral position, and the hydraulic brake generated by the rapid return to the neutral position in HS T is suppressed. It is to prevent.

Next, the operation configuration of the shift pedal 6 8 F · 68 8 R and the arm 1 3 6 will be described.

FIG. 20 is a schematic diagram showing the operational configuration of the pedal, FIG. 20 (a) is an operational configuration during forward travel, and FIG. 20 (b) is a diagram illustrating the operational configuration during reverse travel.

As shown in Fig. 20 (a), when the shift pedal 6 8 F, which is the forward pedal, is depressed, the arm 1 3 6 rotates forward together with the shift pedal 6 8 F. The rod 1 3 7 connected to the H S T operation section is connected to the arm 1 3 6, and the rod 1 3 7 moves forward. As a result, HST is moved forward.

Then, as shown in FIG. 20 (b), when the shift pedal 68 R as a reverse pedal is depressed, the contact arm 145 rotates forward together with the shift pedal 68 R. The contact arm 1 45 is in contact with the roller 1 48 of the L-shaped arm 143, and the L-shaped arm 1 4 3 is rotated backward by the rotation of the contact arm 1 45 forward. The L-shaped arm 143 is configured to rotate integrally with the arms 1 3 6. That is, when the shift pedal 6 8 R is depressed, the arm 1 36 rotates backward, the rod 1 3 7 moves rearward, and the HS T is operated backward.

Next, a configuration for maintaining the shift pedal at a constant angle will be described.

FIG. 21 shows the structure of the speed holding mechanism.

The speed holding mechanism is the speed holding lever that holds the speed 1 5 1, the claw 1 54 that holds the position of the arm 1 3 6, the release arm that releases the engagement between the claw 1 54 and the arm 1 3 6 1 5 5 It is comprised by. The speed holding lever 15 1 is disposed on the front column below the steering wheel, and the upper end of the rod 1 52 is connected to the speed holding lever 15 1. The lower end of rod 1 5 2 is connected to one end of stay 1 5 3 which is pivotally supported. The stay 1 5 3 is provided with a claw 1 5 4 that engages with the arm 1 3 6. The steps 1 5 3 are provided between the body frames 8. Sawtooth-shaped teeth are provided at the front upper part of the arm 1 3 6, and the claw 1 5 4 is engaged with this portion to hold the arm 1 3 6.

By arranging the stay 1 5 3 between the body frames 8 and 8, the speed holding mechanism can be protected by the body frame 8, and the speed holding mechanism is protected and stable while reducing the number of parts. You can get action.

When the speed holding mechanism is in the released state, as shown in Fig. 21 (a), the speed holding lever 1 5 1 is held in a state of rotating downward, and the claw 1 5 4 and the arm 1 3 6 Is disengaged.

As shown in FIG. 21 (b), when the speed holding lever 15 1 is turned upward, the rod 1 5 2 is moved downward and the stage 1 5 3 is rotated downward. Accordingly, the claws 15 4 provided on the stay 15 3 are engaged with the arms 1 3 6, and the positions of the arms 1 3 6 are maintained. The arm 1 36 is connected to the HST operation unit, and since the return force of the HST operation unit is transmitted, the return force to the neutral position is always applied.

The speed maintenance can be canceled by operating the brake. The brake is operated to release the engagement between the arms 1 3 6 and the claws 1 5 4. The arm 1 3 6 and the claw 1 5 4 are disengaged by the arm 1 5 5 interlocked with the brake operation means. The arm 1 5 5 is linked to the brake pedal, and the arm 1 5 5 rotates forward by operating the brake. The stay 15 3 that holds the claw 15 4 has a contact portion that is bent toward the arm 15 5 5, and is configured to be able to contact the protruding portion at the tip of the arm 15 5 5. Therefore, as shown in FIG. 21 (c), when the arm 1 5 5 is rotated forward, the projection of the arm 1 5 5 comes into contact with the step 1 5 3 and the step 1 5 3 Is rotated upward. As a result, the engagement between the claw 15 4 and the arm 1 3 6 is released, and the speed holding state is released.

Next, another embodiment of the speed holding arm will be described. FIG. 22 is a side view of the arm of the speed holding mechanism.

As the arm 1 3 6 constituting the speed maintaining mechanism, it is possible to connect the damper 1 4 4 to the arm 1 3 6 as shown in FIG. As a result, members used for other speed change operations can be simply configured, and the number of parts can be reduced. In addition, since dampers 1 4 4 are connected to the arms 1 3 6 connected to the HST operation unit, resistance due to friction loss and the like can be reduced, and the dampers 1 4 4 can be easily adjusted. In addition, since factors such as friction loss can be reduced, a stable pedal feeling can be maintained.

Next, another embodiment in the arrangement of the shift pedal connecting portion 1 33 will be described.

In this embodiment, the shift pedal connecting portion 1 33 is disposed inside the fuselage frame 8. The shift pedal 6 8 F ′ 6 8 R is disposed outside the fuselage frame 8, and the shift pedal connection portion 1 3 3 is fixed to the inner surface of the fuselage frame 8. As a result, the load received by the shift pedal 6 8 F. 68 R can be received directly by the machine body frame 8, and the load related to the pedal connection portion 1 3 3 can be reduced.

Furthermore, the configuration outside the body frame 8 can be simplified, and when a work machine such as a mid-mount mower is attached, the lifting mechanism and the like can be easily installed.

Next, the configuration of the brake will be described.

FIG. 24 is a side view showing the structure of the brake pedal, and FIG. 25 is a plan view of the same.

The brake pedal 6 1 L · 6 1 R is arranged outside the fuselage frame 8. The brake pedal 6 1 L is rotatably supported by the support shaft 1 81, and is configured to be rotatable relative to the support shaft 1 81. The brake pedal 6 1 R is fixed to the support shaft 1 8 1 and rotates integrally with the support shaft 1 8 1. The support shaft 1 8 1 is horizontally mounted between the body frames 8 and 8, and is supported by the body frame 8 so as to be rotatable. The base of the brake pedal 61 L is provided with an arm that extends obliquely upward and backward, and transmits the movement of the brake pedal 61 L to the rod 140. The brake pedal 6 1 R is fixed to one end of the support shaft 1 81, and the other end is provided with an arm that extends backward and obliquely upward. The arm is connected to rod 1 3 9 and the movement of brake pedal 6 1 R is transmitted to rod 1 3 9 via the arm. The rods 140 · 1 3 9 are respectively connected to the rear wheel braking device, and the left and right rear wheels are braked by sliding the rods 140 · 1 3 9 respectively.

The base of the brake pedal 6 1 L · 6 1 R is provided with arms extending downward, and the arms are connected to connecting members 1 9 2 · 1 9 3, respectively. The connecting members 1 9 2 · 1 9 3 are both connected to the plate 1 9 1, and the plate 1 9 1 is connected to an arm fixed to the support shaft 1 94. The release arm 1 55 of the speed holding mechanism described above is fixed to the support shaft 1 94, and the release arm 1 5 5 rotates by the rotation of the support shaft 1 94 to release the speed holding. Is. The connecting member 1 9 2 · 1 9 3 is connected to the arm that extends below the brake pedal 6 1 L · 6 1 R through a long hole, and is played when one brake pedal is depressed. G 1 9 1 is slid backward to rotate the support shaft 1 94. As a result, the speed hold is released by depressing the brake pedal 6 1 L · 6 1 R.

Next, the configuration of the parking brake will be described.

FIG. 26 is a diagram showing the parking brake mechanism, FIG. 26 (a) is a diagram showing the parking brake operating state, and FIG. 26 (b) is a diagram showing the parking brake released state.

The brake base 6 1 R can be locked to the brake pedal 6 1 L, and the brake pedal 6 1 L · 6 1 R can be rotated together by locking. As a result, when the brake pedal 6 1 L · 6 1 R is depressed, the support shaft 1 8 1 rotates. The parking brake can be made by maintaining the rotation angle of the support shaft 1 8 1. An extension plate 1 8 2 is fixed to the support shaft 1 8 1, and the plate 1 8 2 extends in a direction perpendicular to the support shaft 1 8 1. The plate 1 8 2 rotates integrally with the support shaft 1 8 1, and engagement teeth are formed on the outer edge portion.

In front of the plate 1 8 2, there is an arm 1 8 3. The arm 1 8 3 is rotatably supported inside the body frame 8, and an engaging member 1 84 is fixed to the tip of the arm 1 83. The engaging member 1 8 4 is a rod-shaped member configured in an L shape, and the tip end portion is configured to be engageable with the plate 1 8 2. Then, the engaging member 1 8 4 and the play rod 1 8 2 engage with each other, so that the pivot state of the support shaft 1 8 1 is maintained and the parking brake is applied.

Rod 1 8 5 is connected to arm 1 8 3, and the arm rotates in the front-rear direction in accordance with the up and down sliding of rod 1 8 5. Rod 1 8 5 is connected to a parking brake lever (not shown), and applies the parking brake by operating the parking brake lever while the brake is depressed.

When the rod 1 8 5 is lowered by the parking brake lever, the arm 1 8 3 rotates downward, and the engaging member 1 8 4 engages with the tooth forming portion of the plate 1 8 2. As a result, the rearward rotation of the plate 1 8 2 is restricted, and the parking brake is activated as shown in FIG. 26 (a).

When the rod 1 85 is raised by the parking brake lever, the arm 1 8 3 rotates upward, and the engagement between the engagement member 1 8 4 and the plate 1 8 2 is released. As a result, the parking brake is released as shown in FIG. 26 (b).

In this way, the plate 1 8 2 serving as the latch for the parking brake is disposed between the aircraft frames 8 and 8, and the support shaft 1 8 1 serving as the brake shaft is exposed between the aircraft frames 8 and 8. It is a state. Since the support shaft 1 8 1 is rotatably supported on the machine body frame 8 via a bush or the like, a brake operation mechanism can be simply configured. In addition, an engaging member 1 84 that engages with the plate 1 8 2 serving as a latch is disposed between the body frames 8 and 8. As a result, the brake operation mechanism and parking brake mechanism of the work vehicle can be configured easily and compactly, and the degree of freedom in designing the work vehicle piping configuration and work equipment such as a mid-mount mower can be improved. You can. In addition, the fuselage frame 8 can be actively used as a support member for the brake operating mechanism to reduce the number of parts and the manufacturing cost.

Claims

The scope of the claims

1. A mower tractor with a midmount mower on the lower abdomen between the front and rear wheels,

The input shaft of the mission case is placed on the left and right sides of the fuselage frame, and the input shaft and the output shaft of the engine are connected via a transmission shaft and a universal joint. A mower tractor characterized in that a lifting control device is placed between them.

2. A reinforcing bracket is provided between the left and right airframe frames at the front lower side of the input shaft of the mission case, and the lifting restricting device is disposed on the reinforcing bracket. More tractor.